Grinding machine



Aug. 21, 192s. 1,681,183

J. N. HEALD ET AL 1 GRINDING MACHINE Filed Jan- 30, 1926 3 Sheets-Sheet l J. N. HEALD ET AL K GRINDING MACHINE Flevd Jan. 30, 1926 V3A Sheets-Sheet 2 ,Amami Aug. 21, 1928. 1,681,183

J. N. HEALD ET' AL GRINDIVNG MACHINE Filed Jan- 30, 1926 Zr Sheets-s511681. 3

7172: '(cawz Law Z. ya. s/A

Patented Aug. 2.1, 1928.

UNITED STATES 1,681,183 PATENT OFFICE.

JAMES N. HEALD, OF WORCESTER, MASSACHUSETTS, AND WILLIAM LAW, lOIF' HART- FORD, CONNECTICUT, ASSIGNOIS T THE HEALD MACHINE COMPANY, OF WORCES- TER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

GRINDING MACHINE.

Appiicamn med January so, 192e. serial n. 84,881.

The present invention relates to grinding machines of the type employed for surface grinding, and more especially wherein the faces of successive small flat articles, such as pistonfrings and thel like, are subjected to the action of a grinding wheel.

In previous machines of this type, as exemplified, for instance, by United States Letters Patent to Litt-man, No. 1,361,883, dated December 14, 1920. and by the copending application of William Law, Serial No. 681.163, filed December 17, 1923, now Patent No. 1,582,481, each workpiece, upon its arrival in grinding position, has rotation imparted thereto so as tosubjectfthe entire area of the plane face or surface to be ground to the action of the rotating'grinding wheel,the latter having its axis substantially at right angles to the axis of rotation of the workpiece, and being mounted for sliding4 movement longitudinally of its axis, so asto carry the periphery of said wheel into and out of contact with the surface to be ground.

In such a machine, as the grinding wheel and the workpiece are brought together, the initial contact is between the outer edgeor corner of the workpiece and the corner of the grinding wheel, a condition which leads to excessive wear and attrition of said wheel, especially where the cut'to be taken is a heavy one, inasmuch as in=this initial contact the wheel, at the very beginning, reaches its maximum depth of cut.

The present invention has for its primary object the elimination of the above mentioned difficulties in grinding machines of the surface type, whereby the grinding wheel may be brought into contact with the workpiece without shock, regardless of the depth of cut to be taken, and wherein excessive sparking and chipping and wear of the face or `corner of the grinding wheel is e'ectually avoided. Other and further r objects of the invention will be made apparent in the following detailed description, reference being had in connection therewith to the accompanying drawings, wherein- Fig. 1 is a view in side elevation of a grinding machineembodying the invention.

Fig. 2 is a top plan view of said machine.

Fig. 3 is a longitudinal sectional view, on an enlarged scale, ofthe wheelfcarrying devices of said machine.

Fig. 4'is a top plan view of certain of the parts shown in Fig. 3.

Fig. 5 is a fragmentary detailed view, on an enlarged scale, showin in front elevation the construction at t e right hand end of Fig. 4.

Fig. 6 is a transverse sectional view, certain parts being shown in end elevation, as viewed from the line 6 of Fig. 3.

Fig. 7 is a view similar to Fig. 6, 'showing parts of the machine as viewed from its right hand end. v

Fig. 8 is a diagrammatic view illustrative of the approach of the grinding wheel toward the work, in the operation of the machine.

Fig. 9 is a face view of a cam employed in the machine.

Like reference characters refer to like parts in the different figures.

Referring to Figs. 1 and 2, the machine provides the usual base 1, the latter having suitable slideways 2 and 3, Fig. 7, for the longitudinal reciprocation of a wheel head or carriage 4. The latter, in the manner to be hereinafter particularlydescribed, carries a lrotating grinding wheel 5, which foperates on the faces. of workpieces that are successively disposed in grinding positions beneath said wheel; as herein shown, said workpieces, in the form, for instance, of rings a, a., are

loaded or stacked vertically in a magazine 6,

beneath which rotates intermittently an apertured carrier plate 7. Each movement of said plate 7 brings one of its apertures 8 directly below and in concentric relation to the stack of rings ai, a, at which time the lowermost ring a drops into the aperture 8 and rests against the stationary supporting surface below the plate 7. On the ensuin` movement of plate 7, this ring a is carrie along with said plate, but the superposed rings of the stack are prevented from so moving by the confining action of the magazine 6, as will be well understood. The construction and operation of these work feeding instrumentalities of the machine form no part of the present invention, and hence a detailed description thereof is unnecessary, since such instrumentalities are well known in the art, being shown in the aforesaid patent to Littman, and also in the patent to James N. Heald, No. 1,486,580, dated March 11, 1924. It is sulicient to note that each bis ring a, as removed from the bottom of the stack by the plate 7, is deposited by said plate upon a rotating magnetic chuck 9, whereupon said ring a, rotating with said chuck, has its face ground by the wheel 5, as hereinafter described; then, by a further movement of plate 7, the ground ring a is moved away from grinding position and simultaneously an unground ring. takes its place on the chuck 9.

The wheel head or carriage 4 reciprocates longitudinally on the slideways 2 and 3, this motion being imparted in any well known manner, as by the connection of said head 4, through a rod 10, Fig. 3, to a double acting piston 11, the latter being contained in a fluid pressure cylinder 12 and being actuated by the admission of fluid under pressure to one end or the other of said c linder. Any suitable reversing valve, not siown, may be employed to control the direction of flow of the pressure fluid, said valve being made responsive to the movements of a swinging member 13, Fig. 1. which is acted upon alternately by a pair of longitudinally adjustable dogs or stops 14, 14, carried by the head 4. As will be well understood, the reciprocatory travel of the head 4 is determined by the adjustment and spacing of the dogs 14, 14: such reciprocation, while here shown as effected by hydraulic means, may obviously be effected by any other means well known in the art. According to the present invention, this longitudinal reciprocation of head 4 is not employed, as in previous machines of this type, to move the grinding wheel into and out of contact with the surfacev being ground, but on the contrary, is simply employed to give a traversing action of the grinding wheel across the surface being ground, after the grinding contact, as hereinafter described, has been made, thereby to produce a more nely finished surface, free of grinding lines. In reality, this longitudiiial reciprocation of the head 4 may be dispensed with, without affecting the attainment of the present invention, the latter, as will now be shown, involving a novel departure from established practices iu the manner of obtaining the movement of the inding wheel 5 into contact with the surace of the rotating ring or workpiece ai.

As shown in Fig. 3, the grinding wheel 5 is suitably mounted on a spindle 15, the latter being journalled in bearings 16 and 17 provided by a longitudinally disposed membery 18. The spindle has fastened to it a long drum 15 and by means of a belt 15by and a driving pulley, not shown, said drum and spindle are rotated. At its inner end, said spindle 15 provides a pulley 19, which, by means of a belt 20, Fig. 6, drives a suitable pulley 21, which is mounted on a shaft 22. The member 18, as shown at 23. F ig. 3, provides an opening for the passage of belt 20, and said member 18 on its opposite side portions has flanges 24, 24, whose plane under surfaces have a gradual downward inclination with reference to the axis of spindle 15. These flanges 24, 24 work in similarly inclined slideways 25, 25 provided by the' head 4, and provision is made for causing relative movement between member 18 and the head 4 supporting it, in the following manner As shown in Figs. 3 and 4, the head 4 has suitably journalled therein a transverse shaft 26, the latter carrying a worm wheel 27 which is in mesh with a worm 28 on a shaft 29, journalled in the head 4 at right angles to and below the shaft 26. The shaft 29 receives its rotation, at considerably reduced speed, from a pulley 30, the latter being secured to a sleeve 31 which is loosely journalled on shaft 29. The pulley is driven by a belt 32, Fig. 7, from a pulley 33 on shaft 22, and the rotation of sleeve 31 is impartedV to shaft 29 through the medium of change speed reduction gearing embodying a gear 34 on sleeve 31 in mesh with a gear 35 on a countershaft 36, the latter providing a gear 37 in mesh with a gear 38 on shaft 29. Through this reduction gearing and also through the reduction afforded by the worm drive 27, 28, the shaft 26 is caused to rotate at a very slow speed,-one revolution of said shaft 26 corresponding approximately to the time consumed by a single cycle of operations of the machine, namely the grinding of a single workpiece and its removal from grinding position, accompanied by the movement of an uuground workpiece into grinding position.

Secured to the shaft 26 is a cam 39 which is of the shape shown in Fig. 9, having a raised portion 40, from which the descent is extremelyv gradual for almost the entire periphery of the cam. A roller 41 is carried by the rear end of member 18, in position to make contact with said cam, and a spring 42, Figs. 3 and 4, bearing against a portion 43 of member 18, is effective to thrust said member 18 to the left, relatively to the head 4, thus to press the roller 41 toward the cam 39.

Thus during each revolution of cam 39.

-the member 18, carrying the grinding wheel 5, feeds gradually .downwardly and to the left for nearly the entire revolution of said cam, and then as the portion of cam 39 becomes effective, said member 18 moves quickly upwardly and to the right,the vertical component of the motion being relatively slight, due to the gradual inclination of the ways 25, 25. This upward right hand motion carries the grinding wheel 5 out of contact with the workpiece, and during the engagement of cam portion 40 with roller 41, the finished workpiece is removed from the chuck 9 by a movement of plate 7 and lll) a new unground'work-piece is deposited on said chuck in grinding position; this action of plate'7 may be effected in any well knownl manner, as for instance, by a cani 44, Fig. 1, on the frontend of shaft (5, which at the proper time, actuates a bell crank lever 45, the latter by its movement adapted to secure a single revolution of an actuating member 46, Fig. 2, whereby, through rod 4.7, a single step in the intermittent rotation of plate 7 takes place. Then, following the high portion 40 of cam 39, comes the gradually descending portion for the remainder of its peripher by means of which the member 18, un er the influence of spring .42, feeds gradually to the left and downwardly this motion being partaken of by the grinding wheel 5 and causing the initial contact with the workpiece to be eected by the wheels periphery, as shown in Fig. 8, instead of by the corner of the wheel, as in previous machines of this type. This gradual downward feed brin the wheel and the workpiece into full sur ace contact as soon as any contact whatsoever is Vmade, and from then on the downward feed is gradual 'until the desired depth of cut is reached.

This effectually eliminates the excessive s arking and the chipping and Vattrition of' t e wheel which takes place when the feed, as inv previous machines of this type, is

from the side of the workpiece. The depthv of cut taken by the wheel in the present machine can be regulated very closely by the provision of a threaded adjustable stop member carried by a projection 49 of member 18, and adapted to engage a fixed lug 50 projecting from the head 4, as shown in Fig. 5. When the left hand downward movement of member 18, under the infiuenee of spring 42, has proceeded fai' enough to bring member 48 against lug 50, the feed of the wheel 5 toward the work thereupon ceases, even though the roller 41 may not at such time be bearing against the` radually descending portion of cam 39. T e adjustment member 48 thus affords an exceedingly delicate means for determining the depth of cut of the wheel. Compensation may be made from time to time for wear of the wheel in continued use, by raising the magnetic chuck 9, through the medium of the usual hand wheel 51.

We claim:

1. In a grinding machine. means for imparting rotation to substantially fiat workpieces, a grinding wheel having its axis of rotation substantially at right angles to the axis of work-piece rotation, and means for feeding said wheel into grinding position by movement in a line contained in the angle between said two axes.

2. In a Agrinding machine, a rotating grinding wheel. means for reciprocating said wheel in a path parallel to its axis of rotavpieces into and out of grinding tion, and means for feeding said wheel into Contact with the work surface to be ground, by movement in a direction inclined from the axis of rotation of said wheel.

3. In a grinding machine, a rotating grinding wheel foi` operation on the plane faces 'of work-pieces, said wheel, in the intervals between successive work-pieces, being laterally displaced from grinding position, means for reciprocating said wheel in a path parallel to its axis of rotation, and means for feeding said wheel into grinding position by a movement which brings at once the full Width of the periphery of said wheel into contact with the plane surface to be ground.

y 4. In a grinding machine, means for` imparting rotation to substantially fiat workpieces, a grinding wheel having its axisof rotation substantially at right angles tothe axis of workpiece rotation, means for reciprocating said wheel in a path parallell to its in a line contained in the angle between said two axes. V,

5. In a grinding machine, a rotating grinding wheel, means for successively disposing substantially fiat workpieces in grinding position, means for imparting rotation to the workpieces so disposed. and means operating in timed relation to the disposal of successive workpieces ingrindingposition, for moving said wheel into grinding position, said wheel movement being in a directioninclined from the 4axis of rotation of said wheel.

6. Ina grinding machine, the combination with a reciprocatory grinding wheel .carriage, and means to reciprocate it of a grinding wheel suppoii'l mounted on said carriage for longitudinal movement i-n a direction inclined from the directon of carriage movement, means for moving successive workpieces into and out of grinding position and means for moving said support in timed relation to the movements of successive workpieces into and out of grinding position.

7. In a grinding machine, the combination with a reciprocatory grinding wheel carriage, and means to reciprocate 1t of Vva grinding wheel support mounted on said carriage for longitudinal movement in a direction IMI inclined from the direction of carriage movement, means for moving successive workpieces into and out of grinding position, and means for moving said support in timed relation to the movements of successive workosition, said means including a cam by w ich the grinding wheel is withdrawn from'grindin position, and a spring by which said whee is fed into grinding position.

8. In a grinding machine, the combination with a' rotatable chuck adapted to hold workpieces with fiat surfaces perpendicular to the axis of rotation of said chuck, and a grinding wheel whose cutting face has elements parallel to the surfaces of said Work-4 pieees when held by said chuck. of means for feeding said grinding wheel into grinding contact with the wort-:pieces at an acute angle to their flat surfaces.

9. In a grinding machine, the combination with a rotatable chuck adapted to hold woxkpieees with dat surfaces perpendicular to the axis ot rotation of said chuck, a grinding wheel whose cutting face has elements parallel to the surfaces of said workpieces when held by said chuck. and means to reciprocate said grinding wheel in a path parallel to the surfaces of said workpieces, of means for feeding said grinding wheel into grindingr contact with the workpieces at an acute angle to their fiat surfaces.

10. In a grinding machine. the combination with a rotatable chuck adapted to hold workpieees with flat surfaces perpendicular to the axis of rotation of said chuck. a grindingwheel whose axis of rotation is perpendicular to the axis ot rotation ot said chuck and means to reciprocate said grinding wheel in a line parallel to its axis, of means for feeding said grinding wheel into grinding contact with the workpieces at an acute angle to the axis of said wheel.

ll. In a grinding machine, means for intermittently and successively moving workpieces having a fiat surface into grinding position. means for rotating said workpieces at said position with their fiat surfaces perpendicular to the axis of rotation, a grinding wheel having its axis of rotation substantially at right angles to the axis of workpiece rotation, means for reciprocating said wheel in a path parallel to its axis of rotation, and means for feeding said wheel into grinding position by movement in a line contained in the angle between said two axes.

12. In a grinding machine, means for moving successive workpicces into and outl of a grinding position, means for rotating the workpieces when at said position. a grinding wheel, means for rotating said wheel, a movable support for said wheel by which to carry it into and out of grinding position by movement in a direction at an acute angle to its axis of rotation, and means for moving said support in timed relation to the movement of the said successive workpieces into and out of grinding position.

13. In a grinding machine, a base, slideways provided by said base, a grinding carriage. supported for movement on said slideways, meansto reciprocate said carriage on said ways, a second set of slideways on said carriage located in a plane which hears an acute angle to the plane of the first named slideways. a second carriage mounted for movement on said second slideways, means for reciprocating said second carriage. a grinding wheel, a spindle upon which said grindinflr wheel is mounted, and supports for sai spindle in said second carriage whereby its axis is parallel to the plane of the first named slideways.

JAMES N. HEALD. WILLIAM LAW. 

